Abstract
We cloned a KNOX class1 gene in Physcomitrella patens by RT-PCR and named PpKNOX1 (PpKN1). Champagne and Ashton (2001) reported two KNOX class1 genes, MKN2 and MKN4, and a 267-bp fragment (MKN5). MKN2 was identical to PpKN1. We cloned flanking regions of MKN5. We inserted GUS reporter gene at the end of PpKN1 and MKN5 coding sequence. The transgenic mosses showed GUS activity specifically in egg cells and young sporophytes. Arabidopsis thaliana expressing PpKN1 cDNA under the control of cauliflower mosaic virus 35S promoter showed lobed leaves, which is similar to those in A. thaliana expressing other KNOX class1 genes. These data suggest that PpKN1 and MKN5 functions in meristem formation and maintainance of the sporophyte, which do not form shoot but exists transiently to form seta and sporangium. However, PpKN1 disruptants formed fairly normal sporophytes. We are now producing PpKN1 MKN5 double disruptant and triple disruptants.
